A number of medical patch agents, such as transdermal absorbent and adhesive plaster tape, in which an adhesive layer containing a medicine is mounted on a support have conventionally been made. While such patch agents are required to have such characteristics that they do not peel off even when applied to parts such as joints and faces where movements are large and skins expand and constrict drastically, and neither rash nor flare occurs in the skin even when applied thereto for a long period of time. In the conventional patch agents, those hard to peel off have been likely to generate a rash or flare in the skin and accompany a pain upon peeling off, whereas those less irritative to skins have been easy to peel off.
Therefore, research and development have been under way from the viewpoint of the elasticity of support, the adhesiveness of adhesive layer, and the like in order to satisfy both high peeling prevention (resistance to peel) and low skin irritation (suppression of rashes in the skin and pains upon peeling), and various patch agents have been proposed. For example, Japanese Patent Application Laid-Open No. HEI 9-255563 discloses a technique in which the ratio in length between the longer and shorter sides in a rectangular patch agent and the bending resistance in the longitudinal direction are controlled so as to yield a skin traceability. Also, Japanese Patent Application Laid-Open No. HEI 10-226638 discloses a technique in which a support having a low bending resistance is provided with an adhesive planar substance, so as to provide the support with a softness. Further, Japanese Patent Application Laid-Open No. HEI 11-35453 discloses a patch agent whose adhesive layer contains oleic acid alkyl ester, so as to reduce the peeling force.
Even in the above-mentioned patch agents, however, if the adhesiveness of adhesive layer is fully lowered in order to prevent rashes from occurring, then the skin adhesion becomes insufficient, so that they are easier to peel off. If a sufficient adhesiveness is provided thereto so that they do not peel off even when applied to a part whose movement is large, then the skin is likely to suffer a rash, whereas pains accompany the peeling, where by a vicious circle occurs.
Thus, the conventional patch agents have not yet been sufficient for satisfying opposite characteristics of high peeling prevention (resistance to peel) and low skin irritation (suppression of rashes in the skin and pains upon peeling) with a favorable balance.